One instance is the Alaska Electric Light & Power Co., said General Manager Peter Bibb, who also has such a system in his home on Thane Road.

"If you want to use your local resources, ground source heat pumps are the way to go," Bibb said. "They reduce heating and air conditioning costs."

The AEL&P headquarters was built on Tongsgard Court in 1996 with 22 residential heat pump units so consumers could view this alternative to conventional fuel-burning or electrical boilers or furnaces.

"It's a combination of forced air and radiant heat, in a closed-loop style system with antifreeze," said heating contractor Dick Behrends of Behrends Mechanical, the company that installed AEL&P's heat pumps.

Ground source heating systems, also know as geothermal heat pumps, collect heat from the earth, which maintains a nearly constant temperature year-round, and feed that heat through pipes or coils into a home or business.

A single ground source heat pump is not much to look at: a simple 3-by-4-foot box in the basement connected to an underground, unseen "loop" of pipes. However, what it lacks in aesthetic appeal it makes up for in efficiency.

"We have a three-in-one system. I can heat my house, cool it and heat my domestic hot water off the same system," Bibb said.

Bibb's residence is 1,900 square feet. His heat pump system, evident in radiant floors, cost $19,500. A similar oil heating system would have cost $15,000. Electric baseboard would have cost $4,500.

Even with the high ceilings of Bibb's house, the heat pump makes it comfortable.

"Everything is very constant, more constant than solar or wind. You don't get temperature stratification - hot and cold areas. Everything you touch, from the toilet seat to the sink, is warm."

"Instead of burning a fossil fuel, we are using solar heat soaked up by the Earth," Bibb said. "The thing that makes heat pumps comparable with oil heating systems is that they have 350 percent efficiency. For every dollar you put into electricity (to circulate the Earth's heart), you get $3.50 worth of heat."

According to the International Ground Source Heat Pump Association, headquartered in Oklahoma, the benefits of the pumps are many. They conserve energy, move heat that already exists rather than burning something and creating toxic emissions, and keep indoor air cleaner because outside air is not brought in.

More Juneau residents are looking into heat pumps in domestic applications. Engineer Bill Leighty urged Douglas Mertz and Margo Waring to look into geothermal heat for their house, now under construction in North Douglas.

"We were intrigued by the environmentally friendly concept of using the earth's own heat as the source rather than either burning fossil fuels or using electricity. The system does use a small amount of electricity to run the pump, but since AEL&P generates from hydropower, the system essentially avoids fossil-fuel emissions of any kind," Mertz said.

"It is also, in the long run, economical, with slightly higher initial capital costs but then lower ongoing costs since we are not purchasing fuel to heat the home," he said.